Yealands records improved juice extraction with DT central membrane press

Critical to the process of making wine is the extraction of juice from grape berries. advantages of the Della Toffola design. Extracting the most juice without extracting solids (suspended solids) or phenolics (browning fractions) has always been a pre-occupation for winemakers regardless of the variety or wine region where grapes are grown.

The Della Toffola membrane bag press is different to other grape presses on the market in that it features an elastic pressing membrane fixed to a central beam. In other ‘bag’ presses, the membranes are located on the side wall of the press tank. For this reason Della Toffola membrane presses are colloquially termed central membrane bag presses.

The orientation of the membrane in Della Toffola presses provides many operating advantages. Key amongst these is the provision of a significantly greater degree of juice/wine drain surface area. In other press systems half the stainless steel tank area is taken up by the pressing membrane, losing considerable surface area for effective juice drainage compared with Della Toffola presses.

It is the function of all membrane presses after all, whether they be central membrane or side/lateral bag orientated, for the bag to press grape berries against the drain screen to produce the cleanest juice or wine. With more than 90% of the tank surface area acting as a press screen drain, Della Toffola presses enable a greater volume of juice extraction, and do so more rapidly, efficiently and effectively.

Della Toffola central membrane presses have been sold in the southern hemisphere for well over 30 years but it is only in the last 15 years that winemakers, big and small, have completely understood the advantages of the Della Toffola design. In the last five years in particular, considerable replacement of capital in fast growing wine industries has seen front-end juice extracting technology move away from side bag presses towards central membrane presses.

The list of wineries that have moved away from side bag press designs and adopted Della Toffola press technology include Yealands, based in New Zealand’s Marlborough wine region. The wine company recently ordered a further two Della Toffola PFC 240 presses to replace some side bag presses.

Yealands reports four years of largely consistent data which shows 15-30 additional litres of extraction per tonne of grapes using the Della Toffola press compared to the various side bag presses it also operates. Based on that extraction rate, the payback on investment, whether it be a winery processing 500 tonnes or 50,000 tonnes, is significant.

Other wineries to recently install a Della Toffola press include Drylands (NZ), which installed a Della Toffola 350hL solution last harvest after years of using a side bag press; Idyll (Australia), which took delivery of a PFC 480; Hillersden (NZ), which installed several PFC 240 units; VinLink (NZ), which recently invested in multiple PFC 350 units; and this coming harvest, Marisco (NZ) will acquire Della Toffola presses having previously only had side bag presses.

Della Toffola bag presses draw inspiration from classic basket presses in their design — turn a Della Toffola press on its side and what does it look like? The provision of ample available drain surface has always been a hallmark of a classic basket press.

Della Toffola membrane bag presses deliver a greater volume of juice extraction, and do so more rapidly, efficiently and effectively than other bag presses.

Another feature of basket press extraction that Della Toffola bag presses mimic is the low level of suspended solid extracted. With winemakers seeking to make filtration by rotary drum vacuum filters obsolete in favour of high solids crossflow filters, ensuring juice extractions with the lowest possible volume of suspended solids is key to successful of adoption of this technology. Della Toffola central membrane presses generate significantly lower solids than other presses, providing the downstream investment saving for the future.

Della Toffola bag presses suit smaller wine producers that desire the advantages of basket presses in fine white wine production, sparkling wine production, or are seeking maximum volumes of free run juice extraction. The also suit large- scale wine producers where the PFC 480 can process 130 tonnes of white grape skins loaded at 100m3 per hour with juice draining at 100m3 hour, achieving 2% solids on extraction and yielding 820 litres per tonne within 70-90 minutes.

For further information contact Della Toffola Pacific, or call (03) 9487-1140.

Article first appeared in Grapegrower & Winemaker Magazine